Socket



May 22, 1945. A. J. scHMlTT 2,376,625

SOCKET Original Filed Aug. '7, 1959 www" 4Patented May 22, 19.45

SOCKET Arthur J. Schmitt, Chicago, lli., assignor to Donald B. Alexander, Carl V. Wisner, Jr., and John F. Mannion, as trustees of The Arthur J.

Schmitt Foundation Original application August 7, 1939, Serial No.

Divided and this application December 27, 1941, Serial No. 424,655

1 Claim.

This invention relates to sockets more particularly such as are used in radio apparatus for holding electronic tubes having prong terminals. Such sockets are used also as receptacles for cable terminal plugs where the plug is provided with prongs for making electrical connection with the contact members of the socket.

Among other objects, the invention aims to provide an improved socket of this type which may be produced and assembled in large quantities at low cost and which at the same time has enhanced mechanical and electrical efficiency, particularly for tubes or plugs in which one of the prongs is in the form of a relatively large center pilot pin provided with rotative position fixing means and also itself affording an electrical contact, while-the other prongs or electrodes are of relatively small diameter and as many as say eight in number, the whole being encompassed within a relatively small circular area approximately three-eighths inch radius.

Other objects and advantages will be apparent from the following description, taken together with the accompanying drawing, in which- Figure 1 is an elevational view oi a socket constructed in accordance with the present invention and associated with a radio chassis panel and radio tube, the latter being shown in separated relation, and the chassis portion being in section, the parts being approximately actual size;

Figure 2 is an enlarged plan viewof the socket alone with parts broken away and in section for clearness of description and also with one of the contact members sectioned through its tail; also with another of the contact members shown as it would be spread by the action of a tube prong received therein;

Figure 3 is a vertical section taken on the staggered line 3-3 of Fig. 2 through the spread contact;

Figure 4 is a bottom view of the structure of Fig. 2 and again showing a fragment of the chassis associated therewith;

Figure 5 is a separated view of the center contact shown in previously mentioned figures;

Figure 6 is a development view of the structure oi' Fig. 5;

Figure '7 is a separated view of one of the other contacts shown in previously mentioned views; and

Figure 8 is a plan view of an illustrative retainer spring as shown in section in Fig. 1.

Referring in detail to the illustrative construction shown in the drawing, the radio chassis I0 may have a generally circular opening II therein to snugly receive the socket I2. As here shown. the socket I2 comprises an insulating body I3 desirably formed of molded insulating material such, for example, as a phenolic condensation product commonly known as Bakelite." The body I3 carries the metal socket or contact members specifically, one of which I4 at the center of the body makes contact with the center prong I5 of the conventional electronic tube I8, and the others of which I6, eight in number in this instance, make contact with the corresponding eight prongs I1 of the tube.

The cylindrical molded body I3 while somewhat disk-like, is desirably of materially great thickness with respect to its diameter, and as here shown has a peripheral shoulder I9 which rests upon the upper face of the metal chassis I0, the cylindrical lower end 20 of the body I3 below the shoulder I9 passing snugly downwardly through the opening I l in the chassis. The body lower end 20 has a peripheral groove 2| in which may be seated the retaining spring 22 which locks the body to the chassis, as best shown in Fig. l. One form of such retaining spring 22 is shown in Fig. 8 of triangular shape in which the corners 23 are resiliently disposed in a plane normally offset from the plane of the intermediate parts 24 of the spring 22 thus providing the desired tension after the socket has been placed in position on the chassis.

As best shown in 4, the socket lower end 20 also has a plurality, in this instance, four peripheral notches 25 in one of which may be received the locating projection 26 of the chassis I 0 which extends into the opening II. These notches permit selective rotative positioning of the socket in the chassis with the projection 26 in any one of the notches 25 and thereafter preventing relative rotation of the socket with respect to the chassis.

It will ybe understood that the present invention is not directed to the mounting of the socket just described, this being for purposes of exempliiication, and that other mounting means may be employed, such for instance as an adaptor plate secured to thesocket body and which may beriveted to the chassis as is well known in the art and need not be here specifically described.

Turning now to the interior construction of the socket I2 which is the subject of the present inventicn, the parts within the area dened by ameter, and is spaced approximately three-sixteenths of an inch inwardly from the over-all diameter of the socket. This area contains a plurality, in this instance eight axial passages arranged as a group on the line of an annulus around the center of the socket and uniformly spaced apart therefrom and one from the other. Each of these axial passages includes an enlarged trough-like and desirably wedge-shaped upper end 28 which opens into a counterbore 29 in the upper end of the body I3. This counterbore 29 is offset radially inwardly of a cylindrical recess in the upper end of the socket dened by the circle 21 and providing a shoulder 21a which extends angularly in segments separated by radial ribs 2lb which are upper projections of the walls of the separate axial passages 28. As here shown, the wedge-shaped passage part 28 tapers decreasingly downwardly to a slot 30 which opens through the lower face 3l of the body.

In each of these axial passages is located one of the metallic contact members I8, which is best shown in Fig. 7, comprises a tail 32 and a resilient prong engaging part 33. Each of the contact members I6 is advantageously a one-piece metal stamping having spring temper. When the contact member I6 is assembled with the body part I3 it is put in from the upper end ofthe body and the contact tail 32 passes downwardly through the slot to project from the body lower end, the tail 32 having the soldering hole 34 therein to which a conductor wire may be attached, or the wire may be wrapped around the intermedially reduced part 35 of the tail 32. Downward movement of the contact member in the body is limited by the intermedially cbliquely bent portion 36 of the contact which prevents passageof this part through the slot 30.

Above the bent part 36, the contact member I6 is extended upwardly as at 31 parallel with but offset from the tail 32 and is again obliquely bent at 38 and then continued upwardly as at 39 in a part parallel with the parts 32 and 31 but still further offset from the tailA 32. At its uppermost end the contact I6 is turned horizontally or at a right angle to the passage as at 40 to form the prong engaging portion proper. When the contact member is inserted downwardly as somewhat yieldingly limited by the bent part 36, the bent part 38 rests against the tapered wall ofthe opening portion 28 as at 4I and the free end 42 of the prong engaging part 40 of the contact advantageously rests as at 43 upon the shoulder 21a occurring between therecess defined bythe circle 21 and the counterbore 29. Thus the prong Aengaging part proper 40 ofthe contact member is cushioned for purposes next described.

In the horizontal prong engaging part 40 of the contact member is a perforation 44 through which is received one of the prongs I1 of the tube. As hereA shown, the entire prong Yengaging part 33 of the contact member is advantageously split from its free endl as at 45 on a line 'passing through the center of the perforation 44 and extendingv downwardly to the part 31. The perforation 44 is desirably made by piercing the metal of the horizontal part 40 and drawing it downwardly as best shown at 46 (Fig. 3) to an extent preferably greater than the thickness of the metal itself, thus affording an enhanced contact. surface with the prong. Thus advantageously no.'

metal is removed from the prong engaging part of the contact member and. its split portions are normally in contact substantially throughout until receipt of the prong.

than the prong I1, and the split 45 permits the prong to be received in the perforation 44 with a scraping resilient engagement which not only improves the electrical conductivity therebetween but also is a factor in permitting the contact to accommodate itself to the prong. This is further enhanced by the somewhat floating character of the prong engaging part 33 of the contact member in the trough-like passage part 28. A characteristic of the invention is the controlled resilence of the contacts provided by the structure described which not only prevents breakage of the seal of the tube about the prongs which might otherwise occur due to bending or wedging strain on the prongs, but also prevents distortion of the prong engaging part of the contact member beyond its elastic limit.

When the contact members IG have all been inserted as already described in the body I3, they are retained in position against upward displacement, in the present embodiment of the invention, by an insulating disk 41 also desirably of a phenolic condensation product or the like, which fits snugly in the recess defined by the circle 21 and has openings 46 therethrough registering with the perforations 44 in the contact members respectively, the disk 41 resting upon the ribs 21h and center core 41a, the upper surfaces of which are co-planar, and also substantially ilush with the contact member portions 40 upper surface.

In this instance the disk 41 is retained in position flush with the upper surface of the socket as shown and described by a preformed shoulder 49 on the upper end of the central grommet-like contact member I4 which passes downwardly through a central opening 5I in the disk 41 and a corresponding central axial passage 52 in the socket body I3. Another shoulder, as presently described, is then formed at the lower end of the contact member I4 to complete its grommetlike character and to secure the parts in position.

As shown in the development view, Fig. 6, of this central contact member I4, it is formed of resilient sheet metal and has an initially flat form as at 50 having a somewhat rectangular part 53 forming the deep head of a T-shape figure of which the leg is the part 54 and on each side of which are the tabs 55 depending from the head 53. When, now, the part 53 is bent around upon itself as shown in Fig. 5, it assumes the somewhat cylindrical form of the central contact I4 having the two free wings 56, the free ends 51 of which are turned outwardly while still spread apart and somewhat parallel. When the wings 56 are compressed to insert the central contact I4 in the openings 5| and 52 in the disk and body, the free ends 51 of the contact are resiliently received in an axial keyway 58 formed jointly in the disk 41 and body I3, the preformed shoulder 49 stopping short of the ends 51, which extend vertically for a, materially great distance. Thus the disk 41 and body I3 are held against both axial and rotative relative displacement. Part 54 of the contact member I4 forms a soldering tail similar to the tails 32 of the contact members I6. It may have the soldering hole 59 therein and be off-set as at 60 to place this part nearer the axis of thev socket and away from the other contact members.

, The lower edge 6I of the-blank 50 for the contact I4 maybe 'slightly sheared to form partly separated edge portions 62 which may be bent as at 63 t0 lock the contact in position, and also to complete the grommet-like character of the contact to clamp the socket parts together.

When the tube I8 is inserted in the socket with the relatively large central prong I of the tube passing into the hollow interior of the central contact I4, the radially and longitudinally extending key 64 on the central prong I5 of the tube is received in the axial keyway 58 of the socket, the prong I5 thusacting as a pilot pin by predeterminng the relative rotative relationship of the tube to the socket and determining the particular contact I6 with which each particular tube prong I1 will engage for circuit continuing purposes.

Since, as will be already understood, it is intended that an electrical as well as mechanical connection be established between the central prong I5 oi the tube and the central contact I4 of the socket, for electrical grounding or other circuit continuing purposes, the resilient sliding contact of the prong key 64 with the resilient wing ends 51 of the contact provides a good electrical connection, and this is further enhanced by inwardly directed segmental bulges formed in the contact tab portions 55 which act as spring fingers 65. These spring ngers are yieldingly received in the annular groove 6B near the end of the tube prong I5 with a somewhat snap-button elect, which alsol prevents accidental displacement of the tube upwardly off the socket. These spring ngers 65 are desirably continued each for a substantial distance segmentally on opposite sides of the central contact I4, approximately one quarter of the circumference oi the member I4.

The main portion of the central contact I4. in addition to its other functions, desirably serves as a shield to prevent intercoupling oi current between one contact with its associated prong and another contact with its associated prong.

If desired, additional insulating barriers may be located between the contact passages in the socket, for example, such as the ribs 61 on the lower face 3| of the socket, which lengthen the insulating path for resisting lthe passage of surface electrical currents. Furthermore, these ribs or projections 61 desirably form pockets which prevent resin or soldering ux from ilowing from unie contact to another during the soldering opera on.

While the tails of the contact members may normally protrude at right angles to the lower surface of the socket as shown in full lines in Fig. 1. they may if desired be tanned out by bending them at an angle other than ninety degrees, as shown in dotted lines in Fig. 1, or, as shown in dotted lines in Fig. 4, the contact tails may be twisted out of their normal plane to create a retaining shoulder at the lower face of the socket. thus further securing the contact members against upward displacement and effecting enhanced electrical insulation between contacts by increasing the distance there-between.

The preformed shoulder or flange 49 at the upper end of the central contact member I4 is desirably received in a depression 6B in the disk 41 so as to be flush therewith.

'I'he rim of the lower part 3| of the socket may be extended axially as at 69 to approximately the same extent as the rib-'like projections 61 for, among other things, enhanced electrical insulation.

The insulating body I3 and keeper disk 41 may be further interlocked against relative rotation as at 10. A

So constructed and arranged, the-key 64 is in contact with the free ends 51 substantially throughout the length of the leg, effecting an enhanced scraping electrical contact. The resilient free ends 51 have their extremities turned outwardly but spaced apart and received in the keyway 58 spaced from the walls of the keyway to provide spring flanges whereby they adapt themselves resiliently both to the pilot pin key and to the body keyway.`

This application is a division of my co-pending application Serial No. 288,752., led August '7, 1939, which issued as Patent No. 2,269,993, dated January 13, 1942.

Having described my invention, I claim:

In a socket of the class described, the combination with an insulating body having a central axiall passage and a keyway formed in the side of said passage, of a receiving member disposed in said passage for a central pilot pin of an electrical plug-in device provided with a longitudinal key, said member embodying an initially iiat onepiece resilient metallic stamping bent upon itself to form two free somewhat semi-cylindrical wings with their free ends approaching each other but spaced apart, said free ends having their extremities turned outwardly but spaced apart and received in said keyway spaced from the walls of the keyway to provide free spring flanges, whereby the said spring flanges adapt themselves resiliently both to the pilot pin key and to the body keyway, and means including shoulders at each end of said member for cooperation with the socket 

